Explore the properties of angles formed by two intersecting chords.
1. The intersecting chords form vertical angles. If m<DEB = 105°,
then m<AEC = _

m<DEB = 105°

Given:

The intersecting chords forms vertical angle.

m∠DEB = 105°

To find:

m∠AEC

Solution:

The intersecting chords forms vertical angle.

By vertical angle theorem:

Vertically opposite angles are congruent.

⇒ m∠AEC = m∠DEB

⇒ m∠AEC = 105°

The measure of angle AEC is 105°.

nope.   happens to me as well.

-aparri